1. Isodon ternifolius (D. Don) Kudô, Mem. Fac. Sci. Taihoku Imp. Univ. 2: 140. 1929.
牛尾草 niu wei cao
Plectranthus ternifolius D. Don, Prodr. Fl. Nepal. 117. 1825.
Plants perennial, robust herbs or shrubs. Stems erect, 0.5-2(-7) m, densely tomentose-villous, much branched. Leaves opposite or in whorls of 3 or 4; petiole 2-3(-10) mm; leaf blade narrowly lanceolate to oblong, rarely ovate-oblong, 2-12 × 0.7-5 cm, papery to ± leathery, corrugate, adaxially pilose to villous, abaxially densely whitish or dull yellow tomentose, base broadly cuneate to cuneate, rarely rounded, apex acute to acuminate, rarely obtuse. Spikes terminal and axillary, compact, 9-35 × 6-10 cm; floral leaves similar to stem leaves, gradually reduced, bractlike apically. Calyx campanulate, ca. 2.3 × 2.5 mm, densely gray or dull yellow villous; teeth triangular, equal, ca. 0.5 mm; fruiting calyx dilated, tubular, ca. 4 mm, obscurely veined. Corolla white to purplish; upper lip purple spotted, 5-6 mm. Stamens and style usually included. Nutlets triquetrous, ovoid, ca. 1.8 × 1 mm, glabrous. Fl. Sep-Feb, fr. Dec-May.
Open hills, sparse forests; 100-2200 m. Guangdong, Guangxi, Guizhou, Yunnan [Bangladesh, India, Myanmar, Nepal, Vietnam]